JP2010159046A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a noise without increasing a body size or reducing a cross-section area of an air stream path. <P>SOLUTION: An air conditioner includes a casing 11 that forms a shell of the air stream path in which air flows and stream restraint members 19, 20, 42, and 18a that are arranged in the air stream path spaced from the inner wall of the casing 11 and restrain an air stream in the air stream path, and the stream restraint members are formed of a plate-like sound absorbing material including a porous material or a fibrous material. The stream restraint members are, for example, wall partitions 19, 20 that section part of the air stream path. The wall partition 20 sections, for example, part of the air stream path on a downstream side of a heat exchanger 17 into a plurality of parallel stream paths 21, 22. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an air conditioner having an air flow path through which conditioned air flows, and is suitable for use in a vehicle air conditioner.

  Conventionally, in Patent Document 1, a sound absorbing member is disposed in a bent portion of an air conditioning duct through which air blown out from an air conditioning unit flows, and a portion of the air conditioning duct on the back side of the sound absorbing member is inflated to the outside, so that an air chamber An air-conditioning apparatus that absorbs noise by forming the above is described.

  Further, Patent Document 2 describes an air conditioner that absorbs noise by arranging a resonator-type sound absorbing structure by arranging a plate with a resonance hole at a distance from the front panel inside the front panel of an indoor unit. ing.

  Patent Documents 3 and 4 describe an air conditioner that absorbs noise by disposing a sound absorbing material outside an air conditioning casing that forms an outer shell of an air flow path.

JP 2007-261421 A JP-A-5-71752 JP 2000-85339 A JP-A-11-287471

  However, in the prior art of Patent Document 1, since the air chamber is formed by inflating the air conditioning duct to the outside, the size of the air conditioner is increased by the size of the air chamber.

  In the prior art of Patent Document 2, the resonator type sound absorbing structure is formed inside the indoor unit, so the cross-sectional area of the air flow path formed inside the indoor unit is reduced by the amount of the resonator type sound absorbing structure. As a result, the pressure loss increases.

  Further, in the prior arts of Patent Documents 3 and 4, since the sound absorbing material is arranged outside the air conditioning casing, the size of the air conditioner is increased by the amount of the sound absorbing material.

  In view of the above points, an object of the present invention is to reduce noise without increasing the size of the physique and reducing the cross-sectional area of the air flow path.

In order to achieve the above object, in the first aspect of the present invention, a casing (11) that forms an outer shell of an air flow path through which air flows,
A flow regulating member (19, 20, 42, 18a) that is disposed at a distance from the inner wall of the casing (11) in the air flow path and regulates the flow of air in the air flow path;
The flow regulating member is formed of a plate-like sound absorbing material made of a porous material or a fibrous material.

  According to this, the flow regulating member arranged in the air flow path can also play a role as a sound absorbing material. In other words, noise can be reduced without disposing a sound absorbing structure outside the casing (11) or providing a sound absorbing material separate from the flow regulating member inside the casing (11). For this reason, noise can be reduced without increasing the size of the body and reducing the cross-sectional area of the air flow path.

  According to a second aspect of the present invention, in the air conditioner according to the first aspect, the flow regulating member is a partition wall (19, 20) that partitions a part of the air flow path.

  According to this, since the partition wall can also serve as the plate-like sound absorbing material, the effect of the invention of claim 1 can be obtained with a simple configuration.

In invention of Claim 3, in the air conditioner of Claim 2, it is arrange | positioned at an air flow path, It is equipped with the heat exchanger (17) for a heating which heats the air of an air flow path,
The partition wall (20) is characterized by partitioning a part of the air flow path downstream of the heating heat exchanger (17) into a plurality of parallel flow paths (21, 22).

In invention of Claim 4, in the air conditioner of Claim 2, it is arrange | positioned at an air flow path, It is equipped with the ventilation fan (14) which generate | occur | produces the flow of air,
The partition wall (42) was blown out of the air flow path in the vicinity of the blower fan (14) from the suction flow path (40) through which the air sucked into the blower fan (14) flows and the blower fan (14). It is characterized by being partitioned into a blowout flow path (41) through which air flows.

In invention of Claim 5, in the air conditioner of Claim 1, it is arrange | positioned at an air flow path, The heat exchanger for cooling (16) which cools air,
A heating heat exchanger (17) that is disposed downstream of the cooling heat exchanger (16) in the air flow path and heats the cold air after passing through the cooling heat exchanger (16);
An air mix door (adjusted in the air flow path between the cooling heat exchanger (16) and the heating heat exchanger (17) for adjusting the amount of cold air heated by the heating heat exchanger (17)) 18)
The air mix door (18) has a plate-like door body (18a) that regulates the flow of cold air after passing through the cooling heat exchanger (16),
The flow regulating member is a door main body (18a).

  According to this, since the air mix door can also serve as a plate-like sound absorbing material, the effect of the invention of claim 1 can be obtained with a simple configuration.

In the invention according to claim 6, a casing (11) forming an outer shell of an air flow path through which air flows,
A plate-like rigid member (19, 20, 42, 18a) which is disposed at a distance from the inner wall of the casing (11) in the air flow path and has a predetermined rigidity to perform a predetermined function;
The rigid member is formed of a porous material or a fiber, and also serves as a plate-like sound absorbing material.

  According to this, since the rigid member arranged in the air flow path can also play a role as a sound absorbing material, it is possible to obtain the same effect as the invention described in claim 1 described above.

  In addition, as a specific example of “a plate-like rigid member that fulfills a predetermined function by having a predetermined rigidity” in the present invention, a partition wall that partitions a part of an air flow path, a door main body portion of an air mix door, Examples include a support member that supports various air conditioners (e.g., an evaporator) inside the casing.

  In the invention according to claim 7, in the air conditioner according to any one of claims 1 to 6, the plate-like sound absorbing material (50) is a plate-like soft porous material (50a) as a porous material. The soft porous material (50a) is used by being superimposed and fixed on a plate-like lattice member (50b) made of resin or metal.

  Thereby, both low cost and a sound reduction effect can be achieved. To explain this in detail, when the plate-like sound absorbing material is composed of only a porous material, it is necessary to configure the porous material with a metal such as aluminum having high rigidity in order to obtain sufficient performance. Cost increases. Therefore, in terms of cost, it is desirable to use a soft porous material such as urethane foam as the porous material.

  However, when a soft porous material is used as it is as a plate-like sound absorbing material, since the sound absorbing material vibrates following low pressure due to low rigidity, the damping effect due to friction between the sound absorbing material and the air particles is reduced, and sufficient Sound absorption effect cannot be obtained.

  In this regard, in the present invention, since the highly rigid lattice-like member (50b) supports the soft porous material (50a), the soft porous material (50a) does not vibrate following the pressure fluctuation of the sound wave, A sufficient sound-absorbing effect can be obtained by frictional attenuation between the internal voids and air particles (see FIG. 8 described later). For this reason, both low cost and a sound reduction effect can be achieved.

  In the invention according to claim 8, in the air conditioner according to claim 7, the plate-like sound absorbing material (50) uses a plate-like soft porous material (50a) as the porous material, and the soft porous material (50a) is constituted by sandwiching between two plate-like lattice members (50b, 50c) made of resin or metal.

  According to this, since both the front and back surfaces of the soft porous material (50a) rub against the lattice members (50b, 50c), only one surface of the soft porous material (50a) rubs against the lattice members (50b). Compared to this, it exhibits a greater friction damping effect.

  The invention according to claim 9 is characterized in that in the air conditioner according to claim 8, the two lattice members (50b, 50c) are arranged so that the lattice patterns do not overlap each other.

  According to this, compared with the case where the lattice patterns of the two lattice members (50b, 50c) are overlapped, the two lattice members (50b, 50c) are overlapped to form the soft porous material (50a). Since the area of the sandwiched portion is small, the surface pressure is high in the portion, but the surface pressure is low in other portions.

  For this reason, the movement of the soft porous material (50a) is regulated by a high surface pressure at a place where the two lattice members (50b, 50c) overlap and sandwich the soft porous material (50a), and the surface pressure is low. In other places, the soft porous material (50a) moves relative to the lattice members 50b and 50c to exert a friction damping effect. As a result, a larger friction damping effect can be obtained as compared with the case where the lattice patterns of the two lattice members (50b, 50c) overlap each other.

According to a tenth aspect of the present invention, in the air conditioner according to any one of the seventh to ninth aspects, the air permeability of the soft porous material (50a) is in the range of 1 to 10 cc / cm ² / s. It is characterized by that.

  Thereby, a high sound absorption effect can be obtained. This will be explained in detail. If the air permeability is small, the flow rate through the gap is small, and the energy attenuated by the frictional force is small. On the other hand, if the gap is large and the air permeability is large, the flow rate through the gap is large, but the area where the frictional force is generated is small, and the energy attenuated by the frictional force is small.

Therefore, there exists a range of air permeability that can obtain a high sound absorption effect. Specifically, good results are obtained when the air permeability is 1 to 10 cc / cm ² · s (see FIGS. 11 and 12 described later). ).

According to an eleventh aspect of the present invention, in the air conditioner according to any one of the seventh to ninth aspects, the soft porous material (50a) has a bubble diameter R of 1 mm or less, and is calculated by the following formula: The bubble diameter R and the porosity hg are set so that the flow resistance σ is in the range of 125000 to 1250000 Pa · s / m ² .

但し、ηは粘性抵抗、Ｒは気泡の平均径、ｋは構造因子係数（＝３）、ｈｇは空隙率である。

Where η is viscous resistance, R is the average bubble diameter, k is the structure factor coefficient (= 3), and hg is the porosity.

Thereby, the air permeability of a soft porous material (50a) can be set to the range of 1-10 cc / cm < ² > * s, and a high sound absorption effect can be acquired.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is sectional drawing which shows the indoor unit of the vehicle air conditioner in 1st Embodiment of this invention. It is explanatory drawing explaining the noise reduction effect in the indoor unit of FIG. It is a schematic diagram which shows the measuring apparatus which measures the sound reduction by a plate-shaped sound-absorbing material. It is a graph which shows the measurement result of the volume reduction by the measuring apparatus of FIG. It is sectional drawing which shows the indoor unit of the vehicle air conditioner in 2nd Embodiment of this invention. It is sectional drawing which shows the indoor unit of the vehicle air conditioner in 3rd Embodiment of this invention. It is sectional drawing which shows the plate-shaped sound absorption material in 4th Embodiment of this invention. It is a graph which shows the improvement effect of the vertical sound absorption rate by 4th Embodiment of this invention. It is a graph which shows the improvement effect of the vertical sound absorption rate by 4th Embodiment of this invention. It is sectional drawing which shows the soft porous material in 4th Embodiment of this invention. It is a graph explaining the appropriate range of air permeability about the soft porous material in a 4th embodiment of the present invention. It is a graph explaining the appropriate range of air permeability about the soft porous material in a 4th embodiment of the present invention. It is a graph explaining the definition of the average sound absorption coefficient αm in the effective range. It is sectional drawing which shows the plate-shaped sound-absorbing material in 5th Embodiment of this invention. It is sectional drawing which shows the plate-shaped sound-absorbing material in 6th Embodiment of this invention.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view schematically showing an indoor unit 10 of a vehicle air conditioner according to this embodiment. The indoor unit 10 in the vehicle air conditioner has a casing 11 that forms an outer shell of an air flow path.

  The overall configuration of the indoor unit 10 is broadly divided into a blower unit 12 that generates an air flow in the air flow path and an air conditioning unit 13 that adjusts the temperature of the blown air from the blower unit 12.

  Although not shown, the indoor unit 10 is disposed in an internal space of an instrument panel (not shown) provided in the foremost part of the vehicle interior. More specifically, the air conditioning unit 13 is arranged at a substantially central portion in the vehicle width direction in the internal space of the instrument panel, and the blower unit 12 is arranged offset to the passenger seat side with respect to the air conditioning unit 13. ing.

  The casing 11 forming the air flow path is formed of a resin (for example, polypropylene) having a certain degree of elasticity and excellent in strength. Although not shown in the figure, the casing 11 is divided into a plurality of divided casings for reasons such as die cutting for molding and reasons for assembling the air conditioner into the casing 11. The split casing is integrally fastened.

  The blower unit portion 12 is integrally configured with an inside / outside air switching box (not shown) for switching and introducing inside air and outside air. Although not shown, the inside / outside air switching box is formed with an inside air introduction port for introducing the vehicle interior air (inside air) and an outside air introduction port for introducing the vehicle interior air (outside air).

  The inside air introduction port and the outside air introduction port are switched open and closed by an inside / outside air switching door (not shown) arranged in the inside / outside air switching box. The opening degree of the inside / outside air switching door is adjusted by a servo motor (not shown), and the introduction ratio of the inside / outside air is switched by adjusting the opening degree of the inside / outside air switching door.

  A blower fan 14 that is rotationally driven by an electric motor (not shown) is disposed in the air flow path in the blower unit 12. In this example, as the blower fan 14, a centrifugal blower fan that sucks air from one end side in the rotation axis direction (the front side in FIG. 1) and blows air radially outward is used.

  The air outlet 12 a of the blower unit 12 is connected to the air inlet 13 a of the air conditioning unit 13 through the intermediate duct 15. In the air flow path in the air conditioning unit 13, as an air conditioner for adjusting the temperature of the blown air, a cooling heat exchanger 16 that cools the blown air and a heating that heats the cold air that has passed through the cooling heat exchanger 16 are used. A heat exchanger 17, an air mix door 18 that adjusts the amount of cold air heated by the heating heat exchanger 17, and the like are arranged.

  Specifically, the cooling heat exchanger 16 is an evaporator of a vapor compression refrigeration cycle, and the heating heat exchanger 17 is a heater core that heats blown air using engine cooling water as a heat source. The air mix door 18 continuously changes the air flow ratio of the cold air that passes through the heater core 17 and the cold air that bypasses the heater core 17 among the cold air cooled by the evaporator 16 by continuously changing the opening degree. It is a temperature adjusting means for adjusting the temperature of the blown air by changing.

  The air mix door 18 is a cantilever door having a plate-like door main body portion 18a that regulates the flow of cold air after passing through the evaporator 16, and a rotary shaft 18b disposed at one end of the door main body portion 18a. The opening degree is adjusted by a servo motor (not shown).

  In this example, a left and right independent temperature control type vehicle air conditioner is configured. Specifically, the air flow path downstream of the evaporator 16 in the air conditioning unit 13 is divided into two parallel flow paths 21 and 22 by partition walls 19 and 20, and the two parallel flow paths 22 and 23 are separated. By arranging the air mix doors 18 respectively and operating the air mix doors 18 independently, the air volume ratios of the cold and warm air are adjusted in the two parallel flow paths 21 and 22, respectively, to the left and right two regions in the vehicle interior. Independently control the temperature of the blown air.

  The partition walls 19 and 20 are not only a flow restricting member that restricts the flow of air in the air flow path but also a rigid member having a predetermined rigidity, and are formed of a plate-like sound absorbing material made of a porous material or a fibrous material. Yes.

  One partition wall 19 is disposed between the evaporator 16 and the heater core 17, and the other partition wall 20 is disposed downstream of the heater core 17 in the air flow. Further, the partition walls 19 and 20 are arranged with an interval of a dimension L1 with respect to the inner wall of the casing 11.

  The partition walls 19 and 20 can be fixed to the casing 11 by, for example, sandwiching the partition wall 19 in the casing 11. Further, the partition walls 19 and 20 may be bonded to the casing 11, or the partition walls 19 and 20 may be integrally formed with the casing 11.

  A portion of the parallel flow paths 21 and 22 on the downstream side of the air flow from the heater core 17 constitutes air mix spaces 23 and 24 that mix hot air that has passed through the heater core 17 and cold air that has bypassed the heater core 17.

  Although not shown, a defroster opening, a face opening, and a foot opening for blowing air into the vehicle compartment are formed in the most downstream portion of the casing 11. Two of these openings are formed corresponding to the two parallel flow paths 21 and 22.

  The conditioned air whose temperature has been adjusted in the air mix spaces 23 and 24 is switched by a blowing mode door (not shown) provided on the downstream side of the air flow in the air mix spaces 23 and 24, so that the defroster opening, the face opening, The air is blown into the vehicle compartment through any one of the foot openings.

  Specifically, the conditioned air from the opening of the defroster is blown out from the defroster outlet (not shown) toward the vehicle front window glass via the defroster duct (not shown), and the conditioned air from the face opening is Air is blown out from the face air outlet (not shown) through the face duct (not shown) toward the occupant's face, and the conditioned air from the foot opening is passed through the foot duct (not shown). It blows out from the foot of the passenger (not shown). The blowing mode door is driven by a servo motor (not shown).

  Actuators such as the above-described servo motor that drives the inside / outside air switching door, the electric motor that drives the blower fan 14, the servo motor that drives the air mix door 18, and the servo motor that drives the blowing mode door (none of which are shown). The operation of is controlled by an air conditioning control unit (ECU) (not shown).

  The air conditioning control device includes a known microcomputer including a CPU, a ROM, a RAM, and the like and peripheral circuits thereof. This air conditioning control device stores an air conditioning device control program in its ROM, performs various calculations and processing based on the air conditioning device control program, and operates air conditioning control devices connected to the output side of the air conditioning control device. To control.

  For example, the air-conditioning control device detects the inside air temperature Tr detected by the inside air temperature sensor (not shown), the outside air temperature Tam detected by the outside air temperature sensor (not shown), and the solar radiation detected by the solar radiation sensor (not shown). The strength Ts and the set temperature Tset set by the occupant operating a temperature setter (not shown) are read, and the target blowing temperature TAO is calculated based on these data.

  And an air-conditioning control apparatus determines the control amount of each actuator mentioned above based on this TAO, and controls each actuator based on these control amounts.

  Next, the operation of this embodiment in the above configuration will be described. When the vehicle air conditioner is operated, an electric motor (not shown) in the blower unit 12 rotates the blower fan 14, thereby introducing the inside air or the outside air from the inside / outside air switching box (not shown). It blows toward the part 13. At this time, blade noise of the blower fan 14 is generated.

  The air blown toward the air conditioning unit 13 from the blower fan 14 passes through the air conditioning unit 13 in the order of the evaporator 16 → the air mix door 18 → the heater core 17 and is adjusted to a desired temperature. At this time, wind noise is generated from the evaporator 16, the air mix door 18 and the heater core 17.

  Noise such as blade noise and wind noise echoes in the casing 11 and propagates from the defroster, face, and foot outlets (not shown) to the interior of the casing outside the casing 11 to give the passenger an unpleasant feeling.

  In this regard, in this embodiment, since the partition walls 19 and 20 are formed of a plate-like sound absorbing material, noise is reflected between the partition walls 19 and 20 and the casing 11, and the partition walls 19 and 20 and the casing 11 are Noise can be reduced in a wide band centered on the frequency f1 corresponding to the distance L1 between the two.

  This noise reduction effect will be described with reference to FIG. When the sound wave having the wavelength λ incident on the wall surface of the casing 11 is reflected by the wall surface of the casing 11, the phase is inverted by 180 °, the reflected wave and the incident wave are superposed, and the distance from the wall surface is ¼ of the wavelength λ. The particle velocity is maximized at the location corresponding to.

  The plate-like sound absorbing materials 19 and 20 made of a porous material or a fiber have the principle of attenuating kinetic energy and reducing acoustic energy by friction of air particles in fine gaps formed in the inside. The most effective sound absorption is achieved by installing it at the maximum speed.

  Therefore, when the plate-like sound absorbing materials 19 and 20 made of porous material or fiber are arranged at a distance L from the wall surface of the casing 11 as shown in FIG. 2, the frequency corresponding to L = 1 / (4λ). The sound of f = sound speed c / (4L) can be reduced most effectively. Therefore, as the distance L increases, the sound with a lower frequency can be reduced.

  FIG. 3 is a schematic view showing a measuring device 30 for measuring the sound reduction by the plate-like sound absorbing material. In this measuring device 30, a plate-like sound absorbing material 32 is installed in a position separated from the inner wall of the rectangular duct 31 by a distance L in the rectangular duct 31, and the speaker 33 disposed on one end side of the rectangular duct 31 pinks. Noise is applied and the passing sound that has passed through the rectangular duct 31 is measured by the microphone 34 disposed on the other end of the rectangular duct 31 to measure the effect of reducing the passing sound.

  The speaker 33 is connected to an amplifier 35, and the amplifier 35 is connected to a noise generator 36. The microphone 34 is connected to a sound level meter 37, and the sound level meter 37 is connected to an FFT 38.

  FIG. 4 is a graph showing a measurement result of the volume reduction by the measuring device 30. When the plate-like sound absorbing material 32 is arranged at a distance L = L0 from the inner wall of the rectangular duct 31, when the distance L = 0, that is, the plate-like sound absorbing material 32 is brought into contact with the inner wall of the rectangular duct 31. The sound can be reduced in a wide frequency band centered on the low frequency f0 as compared to the case where the two are arranged.

  When the distance L is twice as large as L0 (L = 2 × L0), the sound can be reduced in a wide frequency band centered on the lower frequency 1 / 2f0.

  As is clear from the above description, in the present embodiment, since the existing partition walls 19 and 20 are formed of a plate-like sound absorbing material, the partition walls 19 and 20 can also serve as a sound absorbing material. In other words, noise can be reduced without disposing a sound absorbing structure outside the casing 11 or providing a sound absorbing material separate from the partition walls 19 and 20 inside the casing 11. For this reason, noise can be reduced without increasing the size of the body and reducing the cross-sectional area of the air flow path.

  Moreover, the echo space dimension L1 can be ensured large by making the partition walls 19 and 20 into a sound-absorbing material. For this reason, sound can be effectively reduced in a lower frequency band than in the past.

  Moreover, according to this embodiment, the reflected wave of the wall surfaces in the casing 11 interferes, and generation | occurrence | production of the resonance phenomenon which a specific frequency sound increases can be suppressed. That is, since the plate-like sound absorbing materials 19 and 20 are normally disposed at the intermediate position of the casing 11, the particle velocity of the sound wave passing through the plate-like sound absorbing materials 19 and 20 can be attenuated to suppress the occurrence of the resonance phenomenon. . Therefore, it is effective for reducing the specific frequency sound.

(Second Embodiment)
In the said 1st Embodiment, although the partition walls 19 and 20 are formed with the plate-shaped sound-absorbing material, as shown in FIG. 5 in this 2nd Embodiment, the door main-body part 18a of the air mix door 18 is made into a plate-shaped sound-absorbing material. It is formed with.

  The door main body 18a is a flow restricting member that restricts the flow of air in the air flow path, and is also a rigid member having a predetermined rigidity.

  According to the present embodiment, sound can be reduced in a wide band centering on the frequency corresponding to the distance L2 between the door main body portion 18a of the air mix door 18 and the inner wall of the casing 11, so that the same as in the first embodiment. Noise can be reduced without increasing the size of the body or reducing the internal air flow path.

(Third embodiment)
In the said 1st Embodiment, the partition walls 19 and 20 which partition the air flow path downstream from the evaporator 16 into the two parallel flow paths 21 and 22 among the air flow paths in the casing 11 are formed with a plate-shaped sound absorbing material. However, in the third embodiment, as shown in FIG. 5, in the air flow path in the casing 11, in the vicinity of the blower fan 14, the suction flow path 40 through which the air sucked into the blower fan 14 flows and the air flow The partition wall 42 is partitioned by a partition wall 42 from a blowing passage 41 through which air blown out from the fan 14 flows, and the partition wall 42 is formed of a plate-like sound absorbing material.

  The partition wall 42 is a flow restricting member that restricts the flow of air in the air flow path, and is also a rigid member having a predetermined rigidity.

  In the example of FIG. 5, the blower fan 14 is disposed between the heater core 17 and the blower outlet 43 of the casing 11, and the blower fan 14 sucks the air after passing through the evaporator 16 and the heater core 17 to the blower outlet 43. It comes to blow out towards.

  Moreover, in the example of FIG. 5, the air mix door 18 is comprised by the slide door which a door main-body part slides. Further, as shown by a two-dot chain line in FIG. 5, a filter 44 for removing dust in the blown air may be disposed on the upstream side of the evaporator 16.

  According to the present embodiment, sound can be reduced in a wide band centered on the frequency corresponding to the distance L3 between the partition wall 42 and the inner wall of the casing 11, so that the size of the physique can be increased and the interior can be increased as in the first embodiment. Noise can be reduced without reducing the size of the air flow path.

(Fourth embodiment)
In each of the above embodiments, the plate-like sound absorbing material 19, 20, 18a, 42 is formed of only a porous material or a fibrous material. However, in the fourth embodiment, as shown in FIG. 50, a plate-like soft porous material 50a is used as the porous material, and the soft porous material 50a is overlaid and fixed on a plate-like lattice member 50b made of resin or metal. .

  More specifically, one soft porous material 50a and one grid member 50b are bonded together by adhesion. In addition, you may fix the soft porous material 50a and the grid | lattice-like member 50b by means other than adhesion | attachment. In the example of FIG. 7, the shape of the lattice member 50b is a cross-shaped lattice shape, but the lattice shape may be other than a cross-shaped character (for example, a vertical lattice, a honeycomb lattice, or the like).

  When the plate-like sound absorbing material is composed of only a porous material as in each of the above-described embodiments, it is necessary to configure the porous material with a metal such as aluminum having high rigidity in order to obtain sufficient performance. Cost increases. Therefore, in terms of cost, it is desirable to use a soft porous material such as urethane foam (foamed urethane) as the porous material.

  However, when a soft porous material is used as it is as a plate-like sound absorbing material, since the sound absorbing material vibrates following low pressure due to low rigidity, the damping effect due to friction between the sound absorbing material and the air particles is reduced, and sufficient Sound absorption effect cannot be obtained.

  In this respect, in the present embodiment, since the lattice member 50b having high rigidity supports the soft porous material 50a, the soft porous material 50a does not vibrate following the pressure fluctuation of the sound wave, and the internal voids and air The frictional attenuation of the particles can provide a sufficient sound absorption effect as shown in FIG. 8, and can achieve both a low cost and a sound reduction effect. In the example of FIG. 8, the normal incident sound absorption coefficient is improved by 0.1 or more as compared with the case where the soft porous material is used alone.

  Therefore, it is preferable that the lattice member 50b is harder and has higher air permeability than the soft porous material 50a. Specifically, the material of the lattice member 50b is preferably a hard nonporous material such as non-foamed resin or nonporous metal, and the lattice spacing of the lattice member 50b is preferably about 10 mm.

Further, by setting the air permeability (breathability) of the soft porous material 50a within the range of ¹ to 10 cc / cm ² · s, the sound absorption is higher than that of a metal porous material such as aluminum as shown in FIG. The rate is improved. FIG. 9 shows an example in which the air permeability of the soft porous material 50a is 5 cc / cm ² · s.

  8 and 9, the normal incident sound absorption coefficient was measured using a sound absorption coefficient and impedance measurement by a sound tube—transfer function method. Measurement of sound absorption coefficient and impedance by acoustic tube-The transfer function method uses an acoustic tube with a sound source at one end and a test piece at the other end. A plane wave is excited in the tube by the sound source, and a wall-mounted microphone or in-tube movement is used. This is a method of measuring the complex sound pressure transfer function between two fixed positions with a microphone, decomposing the incident wave component and the reflected wave component, and calculating the normal incident sound absorption coefficient and the specific acoustic impedance of the sound absorbing material from these components. It is.

Here, the reason why the appropriate value of the air permeability of the porous material for the sound absorbing effect is 1 to 10 cc / cm ² · s will be described. As schematically shown in FIG. 10, in the porous material 60, the bubbles 60a are continuously distributed in the inside thereof, and there are a portion connected as a space between the bubbles 60a and a portion partitioned by a thin film 60b. It has a certain configuration. Air enters and exits both sides of the porous material through a fine gap where these bubbles are connected.

  The sound absorption effect is considered to be caused by a damping effect caused by friction between the air gap and air particles. However, if the air gap is small and the air permeability is small, the flow rate passing through the air gap is small, and the energy attenuated by the frictional force is small. On the other hand, if the gap is large and the air permeability is large, the flow rate through the gap is large, but the area where the frictional force is generated is small, and the energy attenuated by the frictional force is small.

Therefore, as shown in FIGS. 11 and 12, there is a range of air permeability in which the maximum sound absorption effect can be obtained, and good results are obtained when the air permeability is 1 to 10 cc / cm ² · s. 11 and 12 show the sound absorption effect and the measurement of the sound absorption coefficient and the impedance by the acoustic tube-measurement of the normal incidence sound absorption coefficient using the transfer function method, and using the average sound absorption coefficient αm in the effective region as an evaluation index of the sound absorption effect. This shows the relationship between air permeability and air permeability.

  The air permeability in FIGS. 11 and 12 is a test value by the Frazier method, and the test conditions are: differential pressure = 125 Pa, inner diameter of sample shape of soft porous material = φ60 to φ80, and plate thickness t = 10.

11 and 12, in the range where the air layer depth h is 80 mm or less and the plate thickness t of the soft porous material 50a is 10 mm or less, the average sound absorption coefficient αm in the effective region is the air layer depth h and the soft layer It can be seen that good results can be obtained with air permeability of 1 to 10 cc / cm ² · s regardless of the plate thickness t of the porous material 50a.

  However, the average sound absorption coefficient αm in the effective range is defined as the average value of the sound absorption coefficient in the 20% frequency band (−0.2f0 to + 0.2f0) before and after the frequency peak f0 of the maximum sound absorption coefficient as shown in FIG. did. Incidentally, the air layer depth h is the thickness of the air layer between the rigid wall and the sound absorbing material.

Next, a specific method for setting the air permeability of the soft porous material 50a in the range of 1 to 10 cc / cm ² · s will be described. The flow resistance σ of the void of the soft porous material 50a can be approximated by the following formula 1.

但し、ηは粘性抵抗、Ｒは気泡の平均径、ｋは構造因子係数（＝３）、ｈｇは空隙率である。構造因子係数とは、空隙の構造が流体の流れの方向の流体運動にどれだけ寄与するかを示す係数であり、均質で等方性の高い多孔質材の場合ｋ＝３程度になる。

Where η is viscous resistance, R is the average bubble diameter, k is the structure factor coefficient (= 3), and hg is the porosity. The structure factor coefficient is a coefficient indicating how much the void structure contributes to the fluid motion in the direction of fluid flow, and is about k = 3 in the case of a homogeneous and highly isotropic porous material.

According to the air permeability measurement by the Frazier method, the range of the flow resistance σ corresponding to the air permeability of 1 to 10 cc / cm ² · s is 125000 to 1250000 Pa · s / m ² . Therefore, a soft porous material 50a having an average bubble diameter R and a porosity hg such that the flow resistance σ calculated by the above formula 1 is in the range of 125000 to 1250000 Pa · s / m ² may be selected.

  The upper limit value of the bubble diameter of the soft porous material used in the above test is 1 mm. When the bubble diameter is 1 mm or less, it is considered that the relationship of the above mathematical formula 1 holds.

(Fifth embodiment)
In the fourth embodiment, one soft porous material 50a and one lattice-like member 50b are bonded together. In the fifth embodiment, as shown in FIG. 14, one soft porous material 50a is bonded. The material 50a is sandwiched between two lattice members 50b and 50c. The two lattice members 50b and 50c are arranged so that their lattice patterns overlap each other.

  According to the present embodiment, both the front and back surfaces of the soft porous material 50a rub against the grid members 50b and 50c, so that only one surface of the soft porous material 50a rubs against the grid member 50b as compared to the fourth embodiment. , Exerts a greater friction damping effect.

(Sixth embodiment)
In the fifth embodiment, the two lattice members 50b and 50c are arranged so that their lattice patterns overlap each other. However, in the sixth embodiment, as shown in FIG. The shaped members 50b and 50c are arranged so that their lattice patterns do not overlap each other.

  In the present embodiment, compared to the fifth embodiment, the area of the portion where the two lattice members 50b and 50c overlap and sandwich the soft porous material 50a is small. In other places, the surface pressure is low.

  Therefore, the movement of the soft porous material 50a is regulated at a high surface pressure at a place where the two lattice members 50b and 50c overlap and sandwich the soft porous material 50a, and the soft porous material is formed at other places where the surface pressure is low. The material 50a moves relative to the lattice members 50b and 50c and exhibits a friction damping effect. As a result, a larger friction damping effect can be obtained as compared with the fifth embodiment.

(Other embodiments)
In each of the above-described embodiments, an example in which the flow regulating member that regulates the air flow direction such as the partition walls 19, 20, and 42 and the door main body portion 18 a of the air mix door 18 is formed of a plate-like sound absorbing material has been shown. However, the present invention is not limited to this, and a plate-like rigid member that is disposed at a distance from the inner wall of the casing 11 in the air flow path and exhibits a predetermined function by having a predetermined rigidity is formed of a plate-shaped sound absorbing material. Even so, it is possible to reduce the sound in a wide band around the frequency corresponding to the distance between the rigid member and the inner wall of the casing 11.

  Examples of such a rigid member include a support member that supports the evaporator 16 inside the casing 11.

  In each of the above-described embodiments, an example in which the air conditioner of the present invention is applied to a vehicle air conditioner has been described. However, the present invention is not limited thereto, and the present invention is applied to various air conditioners such as a stationary air conditioner. Applicable.

11 Casing 14 Blower fan 16 Evaporator (cooling heat exchanger)
17 Heater core (heat exchanger for heating)
18 Air mix door 18a Door main body 19, 20 Partition wall (flow regulating member, rigid member)
21, 22 Parallel flow path

Claims (11)

A casing (11) forming an outer shell of an air flow path through which air flows;
A flow restricting member (19, 20, 42, 18a) that is disposed at a distance from the inner wall of the casing (11) in the air flow path and restricts the flow of the air in the air flow path;
The air-conditioning apparatus, wherein the flow restricting member is formed of a plate-like sound absorbing material made of a porous material or a fiber.   The air conditioner according to claim 1, wherein the flow restricting member is a partition wall (19, 20) that partitions a part of the air flow path. A heating heat exchanger (17) disposed in the air flow path for heating the air in the air flow path;
The partition wall (20) partitions a portion of the air flow path downstream of the heating heat exchanger (17) into a plurality of parallel flow paths (21, 22). The air conditioner according to claim 2. A blower fan (14) disposed in the air flow path for generating the air flow;
The partition wall (42) includes a suction flow path (40) through which air sucked into the blower fan (14) flows in the vicinity of the blower fan (14) in the air flow path, and the blower fan (14). The air conditioner according to claim 2, wherein the air conditioner is partitioned into a blowout flow path (41) through which the air blown out from the pipe flows. A cooling heat exchanger (16) disposed in the air flow path for cooling the air;
A heating heat exchanger (17) that is disposed on the downstream side of the cooling heat exchanger (16) in the air flow path and heats the cold air after passing through the cooling heat exchanger (16);
It arrange | positions between the said heat exchanger for cooling (16) and the said heat exchanger for heating (17) among the said air flow paths, and adjusts the amount of cold air heated with the said heat exchanger for heating (17) An air mix door (18),
The air mix door (18) has a plate-like door body (18a) that regulates the flow of cold air after passing through the cooling heat exchanger (16),
The air conditioner according to claim 1, wherein the flow restricting member is the door main body (18a). A casing (11) forming an outer shell of an air flow path through which air flows;
A plate-like rigid member (19, 20, 42, 18a) which is disposed at a distance from the inner wall of the casing (11) in the air flow path and has a predetermined rigidity to have a predetermined function;
The air-conditioning apparatus, wherein the rigid member is formed of a porous material or a fiber and serves also as a plate-like sound absorbing material.   In the plate-like sound absorbing material (50), a plate-like soft porous material (50a) is used as the porous material, and the soft porous material (50a) is made of a plate-like lattice member made of resin or metal. The air conditioner according to any one of claims 1 to 6, wherein the air conditioner is configured by being superimposed and fixed on (50b).   In the plate-like sound absorbing material (50), a plate-like soft porous material (50a) is used as the porous material, and the soft porous material (50a) is made of two plate-like lattices made of resin or metal. The air conditioner according to claim 7, wherein the air conditioner is configured to be sandwiched between the shaped members (50 b, 50 c).   The air conditioner according to claim 8, wherein the two lattice members (50b, 50c) are arranged so that the lattice patterns do not overlap each other. The air conditioner according to any one of claims 7 to 9, wherein the air permeability of the soft porous material (50a) is in a range of 1 to 10 cc / cm ² / s. The soft porous material (50a) has a bubble diameter R and a porosity so that the bubble diameter R is 1 mm or less and the flow resistance σ calculated by the following formula is in the range of 125,000 to 1250000 Pa · s / m ^2. The air conditioner according to any one of claims 7 to 9, wherein hg is set.

Where η is viscous resistance, R is the average bubble diameter, k is the structure factor coefficient (= 3), and hg is the porosity.

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